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ba246306 AD |
1 | <?php |
2 | ||
3 | // Simple .ICO parsing. The ICO format is insanely complex and this may | |
4 | // fail to correctly handle some technically valid files, but it works | |
5 | // on the majority I've found. | |
6 | // | |
7 | // jimIcon was written in 2013 by Jim Paris <jim@jtan.com> and is | |
8 | // released under the terms of the CC0: | |
9 | // | |
10 | // To the extent possible under law, the author(s) have dedicated all | |
11 | // copyright and related and neighboring rights to this software to | |
12 | // the public domain worldwide. This software is distributed without | |
13 | // any arranty. | |
14 | // | |
15 | // You may have received a copy of the CC0 Public Domain Dedication | |
16 | // along with this software. If not, see | |
17 | // http://creativecommons.org/publicdomain/zero/1.0/ | |
18 | ||
19 | class jimIcon { | |
20 | // Get an image color from a string | |
21 | function get_color($str, $img) { | |
22 | $b = ord($str[0]); | |
23 | $g = ord($str[1]); | |
24 | $r = ord($str[2]); | |
25 | if (strlen($str) > 3) { | |
26 | $a = 127 - (ord($str[3]) / 2); | |
27 | if ($a != 0 && $a != 127) | |
28 | $this->had_alpha = 1; | |
29 | } else { | |
30 | $a = 0; | |
31 | } | |
32 | if ($a != 127) | |
33 | $this->all_transaprent = 0; | |
34 | return imagecolorallocatealpha($img, $r, $g, $b, $a); | |
35 | } | |
36 | ||
37 | // Given a string with the contents of an .ICO, | |
38 | // return a GD image of the icon, or false on error. | |
39 | function fromiconstring($ico) { | |
40 | $this->error = "(unknown error)"; | |
41 | $this->had_alpha = 0; | |
42 | ||
43 | // Read header | |
44 | if (strlen($ico) < 6) { | |
45 | $this->error = "too short"; | |
46 | return false; | |
47 | } | |
48 | $h = unpack("vzero/vtype/vnum", $ico); | |
49 | ||
50 | // Must be ICO format with at least one image | |
51 | if ($h["zero"] != 0 || $h["type"] != 1 || $h["num"] == 0) { | |
52 | // See if we can just parse it with GD directly | |
53 | // if it's not ICO format; maybe it was a mislabeled | |
54 | // PNG or something. | |
55 | $i = @imagecreatefromstring($ico); | |
56 | if ($i) { | |
57 | imagesavealpha($i, true); | |
58 | return $i; | |
59 | } | |
60 | $this->error = "not ICO or other image"; | |
61 | return false; | |
62 | } | |
63 | ||
64 | // Read directory entries to find the biggest image | |
65 | $most_pixels = 0; | |
66 | for ($i = 0; $i < $h["num"]; $i++) { | |
67 | $entry = substr($ico, 6 + 16 * $i, 16); | |
68 | if (!$entry || strlen($entry) < 16) | |
69 | continue; | |
70 | $e = unpack("Cwidth/" . | |
71 | "Cheight/" . | |
72 | "Ccolors/" . | |
73 | "Czero/" . | |
74 | "vplanes/" . | |
75 | "vbpp/" . | |
76 | "Vsize/" . | |
77 | "Voffset/", | |
78 | $entry); | |
79 | if ($e["width"] == 0) | |
80 | $e["width"] = 256; | |
81 | if ($e["height"] == 0) | |
82 | $e["height"] = 256; | |
83 | if ($e["zero"] != 0) { | |
84 | $this->error = "nonzero reserved field"; | |
85 | return false; | |
86 | } | |
87 | $pixels = $e["width"] * $e["height"]; | |
88 | if ($pixels > $most_pixels) { | |
89 | $most_pixels = $pixels; | |
90 | $most = $e; | |
91 | } | |
92 | } | |
93 | if ($most_pixels == 0) { | |
94 | $this->error = "no pixels"; | |
95 | return false; | |
96 | } | |
97 | $e = $most; | |
98 | ||
99 | // Extract image data | |
100 | $data = substr($ico, $e["offset"], $e["size"]); | |
101 | if (!$data || strlen($data) != $e["size"]) { | |
102 | $this->error = "bad image data"; | |
103 | return false; | |
104 | } | |
105 | ||
106 | // See if we can parse it (might be PNG format here) | |
107 | $i = @imagecreatefromstring($data); | |
108 | if ($i) { | |
109 | imagesavealpha($img, true); | |
110 | return $i; | |
111 | } | |
112 | ||
113 | // Must be a BMP. Parse it ourselves. | |
114 | $img = imagecreatetruecolor($e["width"], $e["height"]); | |
115 | imagesavealpha($img, true); | |
116 | $bg = imagecolorallocatealpha($img, 255, 0, 0, 127); | |
117 | imagefill($img, 0, 0, $bg); | |
118 | ||
119 | // Skip over the BITMAPCOREHEADER or BITMAPINFOHEADER; | |
120 | // we'll just assume the palette and pixel data follow | |
121 | // in the most obvious format as described by the icon | |
122 | // directory entry. | |
123 | $bitmapinfo = unpack("Vsize", $data); | |
124 | if ($bitmapinfo["size"] == 40) { | |
125 | $info = unpack("Vsize/" . | |
126 | "Vwidth/" . | |
127 | "Vheight/" . | |
128 | "vplanes/" . | |
129 | "vbpp/" . | |
130 | "Vcompress/" . | |
131 | "Vsize/" . | |
132 | "Vxres/" . | |
133 | "Vyres/" . | |
134 | "Vpalcolors/" . | |
135 | "Vimpcolors/", $data); | |
136 | if ($e["bpp"] == 0) { | |
137 | $e["bpp"] = $info["bpp"]; | |
138 | } | |
139 | } | |
140 | $data = substr($data, $bitmapinfo["size"]); | |
141 | ||
142 | $height = $e["height"]; | |
143 | $width = $e["width"]; | |
144 | $bpp = $e["bpp"]; | |
145 | ||
146 | // For indexed images, we only support 1, 4, or 8 BPP | |
147 | switch ($bpp) { | |
148 | case 1: | |
149 | case 4: | |
150 | case 8: | |
151 | $indexed = 1; | |
152 | break; | |
153 | case 24: | |
154 | case 32: | |
155 | $indexed = 0; | |
156 | break; | |
157 | default: | |
158 | $this->error = "bad BPP $bpp"; | |
159 | return false; | |
160 | } | |
161 | ||
162 | $offset = 0; | |
163 | if ($indexed) { | |
164 | $palette = array(); | |
165 | $this->all_transparent = 1; | |
166 | for ($i = 0; $i < (1 << $bpp); $i++) { | |
167 | $entry = substr($data, $i * 4, 4); | |
168 | $palette[$i] = $this->get_color($entry, $img); | |
169 | } | |
170 | $offset = $i * 4; | |
171 | ||
172 | // Hack for some icons: if everything was transparent, | |
173 | // discard alpha channel. | |
174 | if ($this->all_transparent) { | |
175 | for ($i = 0; $i < (1 << $bpp); $i++) { | |
176 | $palette[$i] &= 0xffffff; | |
177 | } | |
178 | } | |
179 | } | |
180 | ||
181 | // Assume image data follows in bottom-up order. | |
182 | // First the "XOR" image | |
183 | if ((strlen($data) - $offset) < ($bpp * $height * $width / 8)) { | |
184 | $this->error = "short data"; | |
185 | return false; | |
186 | } | |
187 | $XOR = array(); | |
188 | for ($y = $height - 1; $y >= 0; $y--) { | |
189 | $x = 0; | |
190 | while ($x < $width) { | |
191 | if (!$indexed) { | |
192 | $bytes = $bpp / 8; | |
193 | $entry = substr($data, $offset, $bytes); | |
194 | $pixel = $this->get_color($entry, $img); | |
195 | $XOR[$y][$x] = $pixel; | |
196 | $x++; | |
197 | $offset += $bytes; | |
198 | } elseif ($bpp == 1) { | |
199 | $p = ord($data[$offset]); | |
200 | for ($b = 0x80; $b > 0; $b >>= 1) { | |
201 | if ($p & $b) { | |
202 | $pixel = $palette[1]; | |
203 | } else { | |
204 | $pixel = $palette[0]; | |
205 | } | |
206 | $XOR[$y][$x] = $pixel; | |
207 | $x++; | |
208 | } | |
209 | $offset++; | |
210 | } elseif ($bpp == 4) { | |
211 | $p = ord($data[$offset]); | |
212 | $pixel1 = $palette[$p >> 4]; | |
213 | $pixel2 = $palette[$p & 0x0f]; | |
214 | $XOR[$y][$x] = $pixel1; | |
215 | $XOR[$y][$x+1] = $pixel2; | |
216 | $x += 2; | |
217 | $offset++; | |
218 | } elseif ($bpp == 8) { | |
219 | $pixel = $palette[ord($data[$offset])]; | |
220 | $XOR[$y][$x] = $pixel; | |
221 | $x += 1; | |
222 | $offset++; | |
223 | } else { | |
224 | $this->error = "bad BPP"; | |
225 | return false; | |
226 | } | |
227 | } | |
228 | // End of row padding | |
229 | while ($offset & 3) | |
230 | $offset++; | |
231 | } | |
232 | ||
233 | // Now the "AND" image, which is 1 bit per pixel. Ignore | |
234 | // if some of our image data already had alpha values, | |
235 | // or if there isn't enough data left. | |
236 | if ($this->had_alpha || | |
237 | ((strlen($data) - $offset) < ($height * $width / 8))) { | |
238 | // Just return what we've got | |
239 | for ($y = 0; $y < $height; $y++) { | |
240 | for ($x = 0; $x < $width; $x++) { | |
241 | imagesetpixel($img, $x, $y, | |
242 | $XOR[$y][$x]); | |
243 | } | |
244 | } | |
245 | return $img; | |
246 | } | |
247 | ||
248 | // Mask what we have with the "AND" image | |
249 | for ($y = $height - 1; $y >= 0; $y--) { | |
250 | $x = 0; | |
251 | while ($x < $width) { | |
252 | for ($b = 0x80; | |
253 | $b > 0 && $x < $width; $b >>= 1) { | |
254 | if (!(ord($data[$offset]) & $b)) { | |
255 | imagesetpixel($img, $x, $y, | |
256 | $XOR[$y][$x]); | |
257 | } | |
258 | $x++; | |
259 | } | |
260 | $offset++; | |
261 | } | |
262 | ||
263 | // End of row padding | |
264 | while ($offset & 3) | |
265 | $offset++; | |
266 | } | |
267 | return $img; | |
268 | } | |
269 | } | |
270 | ?> |